54 



SPARKS FROM A GEOLOGIST S HAMMER. 



Lateral Zones are much less tilted, and seem to have been 

 displaced by the up-thrust of the Middle Zone. All the 

 rocks which we have observed belong to the Middle Zone; 

 but in this zone is a huge central mass of unstratified Al- 

 pine granite, or protogine, constituting the loftiest summits 

 of the chain, Mont Blanc, Monte Rosa, Bernina, Jung- 

 frau, Finsteraarhorn, and others, while the contiguous 

 portions, on either hand, consist of masses of vertically 

 stratified schists, as we have seen in Aiguille de Char- 



Jiorin iMteroi Zone 



Middle Zonp 



South Lcttral Zone 



GENERAL STRUCTURE, OF THE ALPS. 



MONT BLANC 



Aicuiucs. noucrs 



LA SAXC CORMEr 



a 



ai Protogine c', Felelspat Kic Seliists 



u', Ci;ystiilline Schists di Dolomitie. Limestone 



t . Anthracitic SfhJsts e .Black Limestone and Schists 



c^ Verrucano r> Gypsum 



StuJer; Ceotooie den jScAneiii 



STRUCTURE OF THE ALPS OF CE^:TRAI. EUROPE. 



moz, Aiguille du Dru and other pinnacles.* By weath- 

 ering, these projecting strata assume the castellated forms 

 so magnificently displayed from the Flegere. The un- 

 stratified protogine, on the contrary, weathers into the 

 class of rounded forms of which Mont Blanc is the type. 

 It is from the loftier " central mass " that the boulders 

 of protogine so abundant along the paths of the glaciers 

 have been transported. 



* Studer, GeologU der Schweiz. 



